1. Field of the Invention
This invention relates to a secondary battery of a proton conductive polymer, particularly the secondary battery, wherein a self-discharge characteristic and cycle characteristics are improved.
2. Description of the Related Art
A secondary battery of a proton conductive polymer consists of a construction, wherein a positive electrode is formed on a positive electrode collector and a negative electrode is formed on a negative electrode collector and these electrodes are piled up via a separator, and an aqueous or non-aqueous solution containing a proton source as an electrolytic solution are filled therein.
A method of forming an electrode consists of preparing slurry by adding a binder to powder of a raw material polymer, which is doped or not doped, and a conductive adjuvant on a collector such as a conductive rubber sheet and forming a membrane from the slurry using a coating means such as a doctor blade. After drying the membrane by heating, the thickness of the membrane is adjusted by press if required and then an electrode of required shape is formed by cutting the membrane.
A battery is constructed by arranging the positive electrode and the negative electrode formed as described above facing to each other via a separator impregnated with an electrolytic solution.
A porous olefinic membrane having both acid resistance and oxidation resistance has preferentially been used as a material for the separator by adjusting a pore size appropriately.
However, the battery of a proton conductive polymer of the prior art had a low self-discharge characteristic and both its capacity and its cycle characteristics were not satisfactory.